Smithsonian:

The James Webb Space Telescope (JWST) and Nancy Roman Space Telescope are revealing the universe’s earliest chapters in extraordinary detail. To help astronomers understand what they are seeing, researchers at the Center for Astrophysics | Harvard & Smithsonian have developed “Lumina,” one of the largest and most detailed simulations ever created of the early universe.

Published in Monthly Notices of the Royal Astronomical Society, the new model recreates how ordinary matter, dark matter and radiation interacted during the universe’s first 2 billion years, giving scientists a powerful new tool to test theories about how the cosmos evolved after the Big Bang. By comparing observations from JWST, Roman and other telescopes with Lumina’s predictions, astronomers can determine whether their understanding of the laws governing the universe remains accurate or whether new discoveries may require them to rethink existing theories.

For centuries, astronomers have observed the night sky and developed increasingly sophisticated models to explain how stars, galaxies and other cosmic structures form. Today, supercomputer simulations allow researchers to transform those theories into detailed predictions. When observations match those predictions, confidence in existing theories grows. When they do not, scientists gain opportunities to uncover new insights about how the universe works. [Continue reading…]